Something tells me MusicBee doesn't play nice with Android and SD cards. The song in question "Autumn Sweater" would cut off after 15 seconds in MusicBee and give a playback error. In BlackPlayer it cut off at 32 seconds. So maybe the file got corrupted. I deleted the whole album, copied it back over and it is fine. No split tracks, album or genre.
Now I wanted to fix another album with an incorrect title. I did it in MusicBee and it says updated, but no changes were actually made. Checked BlackPlayer and nothing changed. So I changed the title in BlackPlayer and it updated, but it didn't update in MusicBee under portable device. So editing the tags in BlackPlayer only changes it in the app. Editing in MusicBee doesn't change anything, maybe something to do with Android permissions.
redwing if you have an Android phone with an SD card would you mind trying this? Try editing a tag in MusicBee and see if it updates on your Android device.